ACUTE ADAPTIVE-CHANGES IN FOOD-INTAKE PATTERN FOLLOWING OLFACTORY ABLATION IN RATS

We determined whether acute compensatory feeding pattern changes after bulbectomy persist on a chronic basis, or whether physiological adapt ation occurs to normalize acute changes. Rats were randomized to olfac tory bulbectomy or sham operation; all had jugular vein catheterizatio n. Food intake, meal number and size were studied during infusion of p arenteral nutrients providing 100% daily caloric intake (PN-100) to mi nimize post-ingestive effects. Rats were randomly assigned to acute (f rom day 14 after operation, PN-100 infused for 4 days, followed by 4 d ays of saline infusion) or chronic study (PN-100 infused for 4 days fr om day 40, followed by 4 days of saline infusion). After olfactory abl ation, acutely decreased meal size was offset by increased meal number , but 40 days after, baseline differences between meal size and number no longer existed. No qualitative differences in response to PN-100 w ere noted between acute and chronic groups. Findings suggest a functio nal adaptation of food intake regulatory mechanism between 14 and 40 d ays after bulbectomy.